The traditional way of extending length of a steel bar by lap joint, has problems of slow binding speed and insufficient binding strength. In order to apply the steel bar in various specifications of buildings and effectively solve aforesaid problems, the constructor usually uses a steel-bar coupler to joint two steel bars for solving the problem of the steel bar having insufficient length. In order to facilitate to illustrate the application background of the present disclosure in the following paragraphs, the necessary process performed on the steel bar before joint is described below.
(1) First, an unprocessed steel bar has a bamboo-shaped structure or a structure with spiral sections, but not an ideal cylinder structure, so the manufacturer must extrude a part of the steel bar adjacent to an end head of the steel bar to be a round bar by a cold roll forming process.
(2) Next, a steel bar turning device is used to perform turning process on the part of the steel bar adjacent to the end head of the steel bar, to shape the part of the steel bar adjacent to the end head of the steel bar to be a round bar or a cone.
(3) Finally, a steel bar thread rolling device is used to perform thread rolling process on the round bar or cone to roll male threads on the round bar, so as to form a coupling head.
Therefore, when jointing the two steel bars, the manufacturer just needs to screw the male threads of the steel-bar coupling heads into female threads of a steel-bar coupler, thereby jointing the steel bars integrally. Because the steel-bar coupling head is an important key of affecting the joint strength and stability of the steel bar, how to improve the efficiency, quality and yield rate of steel-bar coupling head production is a core technology on which every manufacturer pays most attention. An objective of the present disclosure is to design a making machine to easily and quickly manufacture the high quality of steel-bar coupling head by automatic operation and management.